Method for extraction of nicotine from tobacco raw material

ABSTRACT

The invention relates to methods of nicotine extraction from tobacco, caporal and tobacco crumb. 
     The proposed method for extraction of nicotine from tobacco, caporal and tobacco crumb implies continuous extraction from raw material with low-boiling solvents at vapor phase followed by solvent stripper and recurrence for further reuse in the process. 
     The technological advantages are the opportunity to use both primary raw material and production wastes, shorter time required for extraction, cost reduction and process simplification for extraction of nicotine, reduction of concomitant substances in the target product, and no need in using acids. 
     These advantages are achieved by the proposed extraction method with low-boiling organic solvents what results in lower consumption of chemicals, lower temperature, shorter time required for the process and additional purification of the target product and eliminates needs for high pressure to be used in technological process.

CROSS REFERENCE TO RELATED APPLICATION

This is a conventional application based on KZ Patent Application No. 2007/0762.1, filed Jun. 5, 2007.

TECHNICAL FIELD OF THE INVENTION

The invention relates to methods of nicotine extraction from tobacco, caporal and tobacco crumb.

BACKGROUND OF THE INVENTION

There is a known method for extraction of nicotine from tobacco with carbon dioxide, nitrous oxide, argon, sulfur hexafluoride [U.S. Pat. No. 4,153,063, May 8, 1979]. The extraction is performed at temperatures 50-70° C. and pressures up to 1,500 atm. (preferably 70-350 atm.); then temperature and pressure are set lower and nicotine is extracted from the gas flows using sorbents.

For example, for 1 kg of tobacco with adjusted water content of 15% to 25%:

-   -   CO₂, 70° C.; 300 atm; the gas:tobacco weight ratio is between         4.9:1 and 6.3:1;     -   CO₂, 50° C.; 1,000 atm; the gas:tobacco weight ratio is between         7:1 and 9:1;     -   Argon, 20° C.; 320 atm; the gas:tobacco weight ratio is between         3.5:1 and 4.5:1;     -   SF₆, 70° C.; 300 atm; the gas:tobacco weight ratio is between         6:1 and 10:1.

Disadvantages of this method are:

-   -   Some hardly available gases, in particular, sulfur hexafluoride,         argon and nitrous oxide are required;     -   Supercritical pressure

In this method, there are indications that it is possible to utilize halogenhydrocarbons, but the conditions are not specified.

There is a known method for extraction of nicotine from tobacco and caporal with nicotine distillation by steam followed by precipitation with phosphotungstic acid: for each 2 g of tobacco, it is required 34-36 g of sodium chloride, 14-15 ml of 8H sodium hydroxide water solution, 8 ml of 5.6% of percipient's solution (phosphotungstic acid) [SU Patent No. 728831, publ. BI No. 15, 1980].

Disadvantages of this method are that it is need a special installation for distillation of quite complex design and using expensive phosphotungstic acid for precipitation—this acid is conventionally used for qualitative analysis at identification of alkaloids, but is not particularly specific for nicotine [Shmuk, A. A., The Chemistry and Technology of Tobacco, Pishchepromizdat, Moscow, 1953, p. 225].

There is a known method for extraction of nicotine from tobacco using organic solvents hardly miscible or immiscible with water and consequent treatment of the extracts by the acid-water solution.

In this method for each kilogram of tobacco, it is required 25-200 l of solvent per hour. Dichlormethane, benzol, cyclohexane, diisopropyl ether, 1,1,1-trichloroethane, trichloroethylene, 1,2-dichloroethane, tetrachloride ethylene are used as solvents [CA Patent No. 809968, 1969-04-08].

For example, tobacco is treated by a flow of organic solvent hardly miscible or immiscible with water and then extraction from the solvent is performed by acid-water solution. In order to assure uniform extraction and achieve economy of the method, extraction of tobacco with organic solvent and extraction from solvent with acid-water solution are realized in continuous process at counter-flow of the two feeds. At that, the contact time for tobacco and organic solvent comprises 45-180 min using a solvent to tobacco ratio of 25-200 l of solvent per 1 kg of tobacco per hour. Acid-water solution is removed at nicotine content from 5% to 25%; removed solution is replaced with the appropriate quantity of clean acid-water solution and extracted tobacco is continuously removed with residual organic solvent in it (in the amount of 1.5-4 l per 1 kg of tobacco); then organic solvent is evaporated and regenerated.

Disadvantages of this method include:

-   -   large consumption of solvents (25-200 l), i.e. the raw         material:extractant weight ratio is between 1:10 and 1:100;     -   extraction with organic solvent is performed in 2 stages, at         pH=2.0 and 2.5 by acid treatment of the extract (using         chlorine-hydrogen acid, sulphuric acid or orthophosphoric acid);     -   the above-mentioned acids may cause corrosion of the equipment.

SUMMARY OF THE INVENTION

An object of the invention is to provide a method for extraction of nicotine from tobacco and caporal as well as from waste products (from a tobacco crumb).

Another object of the invention is to provide a possibility for processing of primary raw materials and production wastes, a shorter, less expensive and technologically simple nicotine extraction, lower contents of accompanying substances in the target product and elimination of usage of acids.

These objects are achieved by the method for extraction of nicotine from tobacco raw material using extraction treatment of raw material by means of organic solvent and subsequent solvent stripping, but unlike the previously known methods, there are used the low-boiling solvents (petroleum ether, chloroform, methylenechloride) at the raw material:solvent weight ratio of about 1:3; tobacco, caporal, and tobacco crumb (production waste) are used as the raw material, and extraction of nicotine is carried out for around 5 h in vapor phase.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

The proposed method makes it possible to reduce the ratio of raw material to solvent, to re-use the solvent stripper at extraction, eliminates need for high pressure, high temperature, acids used in extraction, that improves quality of nicotine, reduces equipment corrosion and, in turn, decreases production cost.

The present invention makes it possible:

-   -   to use easily accessible low-boiling extractants;     -   to carry out the one-stage continuous process during 5 hours         with temperatures not exceeding 70° C. and subsequent         concentration of extracts at boiling temperatures of extractants         (petroleum ether—T_(boil)=40-70° C., chloroform—T_(boil)=65° C.,         methylenechloride—T_(boil)=40° C. at 760 mm Hg);     -   to use any tobacco raw material, tobacco waste and any         extraction performance at normal pressure;     -   to reduce the raw material:extracant weight ratio to 1:3.

Example 1

A mass of 100 g of crushed tobacco raw material was inserted into the paper cartridge of a Soxhlet extraction apparatus; 300 ml of petroleum ether was placed in a flask (the raw material:solvent weight ratio 1:3) and was refluxed at 40-65° C.

The percent extraction of nicotine at the extraction time of 2 h, 3 h, 4 h, 5 h, and 6 h were respectively 72.5%, 80.7%, 86.6%, 89.2%, and 90.5%.

Example 2

A mass of 100 g of crushed tobacco raw material was inserted into the paper cartridge of a Soxhlet extraction apparatus; 300 ml of petroleum ether was placed in a flask (the raw material:solvent weight ratio 1:3) and was refluxed at 60-65° C.

The percent extraction of nicotine at the extraction time of 2 h, 3 h, 4 h, 5 h, and 6 h were respectively 66.4%, 71.1%, 78.9%, 83.5%, and 84.2%.

Example 3

A mass of 100 g of crushed tobacco raw material was inserted into the paper cartridge of a Soxhlet extraction apparatus; 300 ml of petroleum ether was placed in a flask (the raw material:solvent weight ratio 1:3) and was refluxed at 40° C.

The percent extraction of nicotine at the extraction time of 2 h, 3 h, 4 h, 5 h, and 6 h were respectively 68.9%, 75.3%, 84.2%, 86.8%, and 87.6%.

Therefore, the advantages of the proposed method include:

-   -   wider range of nicotine-containing raw materials for commercial         processing;     -   cheaper extraction process due to utilization of cheaper         extracants and absence of expensive equipment, of gas extraction         at high pressure, of expensive and environmentally hazardous         acids (phosphotungstic, hydrochloric, orthophosphoric or         sulphuric acids);     -   lower concentrations of accessory agents in the target product. 

1. A method for extracting nicotine from a tobacco raw material using an extraction treatment of the raw material by means of an organic solvent and subsequent solvent stripping which comprises using as solvent a low-boiling solvent, the raw material:solvent weight ratio being about 1:3; and carrying out the extraction of nicotine for around 5 h in vapor phase.
 2. The method according to claim 1 in which said low-boiling solvent is selected from the group consisting of petroleum ether, chloroform, and methylenechloride and mixtures thereof.
 3. The method according to claim 1 in which said tobacco raw material is selected from the group consisting of tobacco, caporal, and tobacco crumb.
 4. The method according to claim 2 in which said tobacco raw material is selected from the group consisting of tobacco, caporal, and tobacco crumb. 